The present invention relates to surgical face masks and more particularly to a mask having a vapor barrier for preventing clouding or fogging of optical aids used by a wearer of a surgical face mask.
Surgical face masks are worn by surgeons and others in operating and the like to substantially prevent the contamination or infection from airborne bacteria exhausted from the breath of the wearer. Surgical masks are generally lightweight in construction and contain several features designed for adaption to an individual wearer's features. There is often incorporated within the mask, along the upper edge, an elongated, deformable strip having sufficient stiffness to retain the shape given it. In this way, the upper portion of the mask may be contoured to the wearer's face to improve the upper edge fit. A relatively thin strip of soft foam material is sometimes found along this upper edge to increase the comfort of the wearer.
Although the upper edge may be contoured in a variety of facial shapes to most closely approximate the wearer's features, it is inadequate to prevent the wearer's breath from being vented between the face of the wearer and the mask. Since these masks are not designed to obstruct breathing, but rather to provide a breath filter, some breath exhausts through the upper portion of the mask into the vicinity of the wearer's eyes. The breath, being warm and moist, holds fluid vapor which readily condenses on cooler objects. Such cooler objects may be present in the airconditioned operating rooms in the form of glass lenses of optical aids used by the surgeons and assistants. Such optical aids include spectacles, surgical loupes and surgical microscopes.
The exhaust of exhaled breath is resisted to some degree by the mask itself, promoting flow of breath under the mask edges. Because warm air rises, the wearers breath also has a natural tendency to rise under the upper mask edge and through the upper mask surface area producing fogging of the optical aids positioned in the vicinity of the wearer's eyes. This obscuration of the wearer's vision is a nuisance at best and a hazard at worst. This shortcoming of the prior art mask often requires the surgeon to pause to clear the lenses of condensation interfering with his or her vision. The necessity for clear vision during surgical procedures as well as the time expediency element has fostered a need for preventing such fogging.